Re: He-100 Part II- He P.1079 vs Me 509


Kyle Boatright wrote:
"Rob Arndt" <B44Thunder@xxxxxxx> wrote in message
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Kyle Boatright wrote:
"Rob Arndt" <B44Thunder@xxxxxxx> wrote in message
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Kyle Boatright wrote:
"Eunometic" <eunometic@xxxxxxxxxxxx> wrote in message
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max wrote:
"Eunometic" <eunometic@xxxxxxxxxxxx> wrote in message
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P.1079 would have been a beautifull aircraft; its awesome
expected
speed of 560mph with a Jumo 213J or DB603L would surely have been
near
the limit for any piston fighter.

Could this speed really have been achieved? When I first saw it I
read
it
as manufacturer's overclaim.

I think its quite realistic. The Germans had access to a 14 inch
supersonic wind tunnel since 1934. The first US unit wasn't built
in
the US till 1942 and it was smaller and suffered from condensation
problems. It was built by Eastman Jacobs using unauthorised
funding.
Jocobs was the man that gave the world the NACA 4 and 5 digit
airfoils
and invented the laminar flow wing.

big snip>>>

Consider that in the late '80's and early '90's, a group which
included
Lockheed Skunkworks aerodynamicists designed an unlimited racer known
as
Tsunami. At their disposal, these engineers had all the aerodynamic
knowledge generated before, during, and for 45 years after WWII. The
result
of their design looked like a slightly smaller, cleaned up Mustang.
Even
without armor, weapons, self sealing tanks, external antennae, and the
dozens of other performance compromises built into production
fighters,
the
Tsunami was essentially a 500 mph airplane at Reno altitudes. And
that's
with an engine in racing tune, running far closer to the margins than
anyone
would operate an engine that had to perform day in and day out.

Look at the other competitive unlimited racers. The aircraft are
stripped
of military equipment. The canopies are cut down. The engines are run
at
ridiculous power settings, and are guaranteed to come to a bad end if
the
induction cooling system so much as burps. Again, these are 500 mph
aircraft. Rare Bear, arguably the fastest of these aircraft holds the
FAI
record for speed for a piston engined aircraft. 528 mph, using ~3,800
hp.
A modified mustang (modifications not specified, but the engine was
rated
at
3,000 hp), holds a 15/25 km straight course record at 516 mph.

Without HUGE horsepower increases, a much smaller airframe, or
tremendous
sacrifices in other performance characteristics, 560 mph isn't
possible
for
a piston engine fighter.

KB


Utter BS. The Me Bf 109 latter models, including up to the 509 would
have had DB 605N engines at some point and the speed would have jumped
into the mid 500s. The Supermarine Spiteful Mk.XVI reached either 504
or 509 mph in one unofficial test in 1945. It's regular max. speed was
490 mph and could have been raised with upgraded engine. Even the
Australian CAC-15 Kangaroo of the early postwar years reached 502mph
with a Griffon 2,305 hp engine. Both Allied and German/Japanese late
war engines and project engines were to be in the 3-4,000 hp range...
so how do you arrive at your absurd conclusions. Germany had the He-100
@ 464 mph and the Me-209 @ 469 mph PRE-WAR. By war's end Germany had
normal armed fighters of 472 mph (Fw Ta 152) and 477 mph (Do-335). That
mystery Espenlaub on another thead may also have been a 500 mph fighter
as well as the other Luftwaffe X-Plane there- which incidentally has a
mid-fuselage mounted Deutz Dz-710 16 cylinder 3,100 hp engine,
aerodynamic spinner/nose with a 4-bladed prop. Another possible 500 mph
contender.

Rob

p.s. Even that scavenged part circular Sack A.S.6, if reworked by
Messerschmitt and given the K-4's DB 605ASCM of 2,000 hp could have
been brought up to 500 mph.

Power required increases in proportion to the cube of the "after" speed
divided by the "before" speed. So, to go from a 500 mph prop driven
aircraft, which seems to be the practical maximum, to a 560 mph aircraft
would take 40% more horsepower ((560/500)^3) = 1.4. Even then, at those
speeds, it'll take far more power than the calculations show, because the
prop blades are going transonic along much of their span and are
supersonic
at the tips, resulting in a huge efficiency loss. The unlimited racers
work
very hard to minimize those effects and they are at 500 mph down at 5k
feet
where the air is thick and the speed of sound is relatively high.

Going beyond the aerodynamics, propeller and reciprocating engine
technology
matured in WWII. The only way to reliably produce more power was a
bigger
engine. That bigger engine required a bigger airframe, which eliminated
most
or all of the speed advantage that might have been gained through
increased
power. There is a reason a very immature technology (jets) replaced a
very
mature technology (piston/prop's) in the mid '40's. The mature
technology
was at its limits. The engineers realized this.

Dig up all of the paper airplanes and wunderweapon websites you'd like,
but
the physics don't change.

KB


The Germans had supersonic wind tunnels and had already tested a wide
array of prop a/c with the data available. I don't remember reading
anywhere in the detailed Projekt a/c books where a prop threshold was
established.

Here are just some of the 500+ prop projects:

He Lerche I 500 mph
Fw w/As-413 509 mph
Bv P.170.01 510 mph
Do P.273 518 mph
Fw Flitzer I 525 mph (turboprop)
He P.1076.01 534 mph
Do 435 537 mph
He P.1076.03 546 mph
Fw Flitzer II 549 mph (turboprop)
He P.1068.01 565 mph

Rob

Paper weapons. When you transition from paper to an actual flying airframe,
physics takes over and pipedreams go bust.

The claimed speeds prove that either:

A) German designers were willing to make wildly optimistic performance
projections in order to get funding/approval for their projects.

B) There were plenty of German designers who didn't have a good
understanding of the issues they faced in trying to squeeze additional
performance out of a technology that was at its limits.

Again, consider that unlimited racers are hard pressed to reach 500 mph,
much less exceed it by a meaningful margin. What does that tell you about
500 mph + performance projections for operational aircraft?

KB

Maybe they should just get a German to build a racer then! Why not
since the He-100 and Me-209 held the records pre-war!

You know, people that used science said man could not fly
- Lilienthal proved them wrong with his gliders and Count Zeppelin with
his airships

then people said it was impossible to build heavier than air craft
- Gustav Weisskopf proved them wrong in 1901 with his GW No.21

then people said that all-metal a/c could not be built effectively
- Junkers proved them wrong with the CL.1 at the end of WW1

then there was the idea only prop aircraft could fly

- Opel proved them wrong with solid rockets in the late 1920s along
with Espenlaub
- followed by hybrid prop/liquid rocket a/c He-112, He-118, Fw-56, even
a Ju-88 testbed
- followed by the He-176 rocketplane
- followed by the He-178 turbojet
- followed by the He-280 designed jet fighter
- followed by the Me-262 jet fighter
- followed by the Me-163 rocket fighter
- followed by the Ar-234 jet bomber
- followed by 11,000 tons of German documents and windtunnel data at
Wright Field

today they still can't get an ornithopter to fly
- Schmid flew his during WW2 in 1942

Nothing is impossible when Germans are involved. Even the 1940 Mercedes
T80 LSR car with a 3,000 hp DB 603 engine installed was to be able to
hit 469 mph on land! The war cancelled the annual event but the car
survived. If a car on land in 1940 could attain 469 mph on land, then
by late 1945/early 1946 an a/c certainly could go 560 mph.

Please provide undeniable evidence that there is a prop a/c threshold
speed that cannot be broken... like that "sound barrier" thing!!! Also,
please reference the Martin Baker M.B.7 Blackbess proposed a/c of 1947.
It's in my last book.

Rob :)

.

Relevant Pages

  • Re: He-100 Part II- He P.1079 vs Me 509
    ... P.1079 would have been a beautifull aircraft; ... No inovations, same engine just hot roded, in a smaller ... The Tsunami is credited with unofficial speeds of 530mph and 557 on ... racing airframe, not a combat rigged, production airframe. ...
    (rec.aviation.military)
  • Re: He-100 Part II- He P.1079 vs Me 509
    ... P.1079 would have been a beautifull aircraft; ... Tsunami was essentially a 500 mph airplane at Reno altitudes. ... would operate an engine that had to perform day in and day out. ... How many of them ever flew at these speeds ...
    (rec.aviation.military)
  • Re: He-100 Part II- He P.1079 vs Me 509
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  • Re: He-100 Part II- He P.1079 vs Me 509
    ... P.1079 would have been a beautifull aircraft; ... Tsunami was essentially a 500 mph airplane at Reno altitudes. ... would operate an engine that had to perform day in and day out. ... The claimed speeds prove that either: ...
    (rec.aviation.military)
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